(CNN) – Two-thousand-thirteen promises to be an interesting political year - with two governors races that will be closely watched, the very real possibility of another special Senate election in Massachusetts, a possible debate in Washington over immigration reform as the political clout of Latinos continues to grow, and a planned push by Democrats for gun control measures.

(CNN) – The first of four debates - three presidential and one vice presidential - in the final month of the election takes place October 3 in Denver. While we would love to tell you what will happen, the CNN Crystal Ball is out of order. Instead, our best guess of what to expect comes from debates past. Here's a look back, by the numbers, of the trends and surprises of past debates.

61: Percent of households that watched the third debate between John F. Kennedy and Richard Nixon on October 13, 1960.